The Ready State Virtual Mobility Coach is like having a virtual Kelly Starrett in your pocket.
The cause could be improper technique.
If you don’t have the proper mechanics for running or for a certain lift this is causing the pain in your back.
Have someone video you doing the movement so you acn see exactly what is going on.
Seeing it adds another level of understanding to the movement pattern.
Do you have tight areas/muscles in your lower body?